Baxi
Baxi 102005 Honeywell Thermocouple
Baxi thermocouple (Honeywell Q309A2721), part BAXI102005, for gas-fired heating appliances; senses flame heat to hold the gas valve open.
At a glance
- Part type: Thermocouple
- Also known as 1110952
- This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.
Showing prices
£35.28
£29.40 ex. VAT · VAT at 20%
In stock
Cut-off passed — dispatches next working day
Not certain it's the right part? The technical team verifies fitment before dispatch — no charge, and it stops a second trip.
Same-day dispatch
Ordered by 4pm Mon–Fri, 10:30am Sat.
30-day returns
Unused, in original packaging.
What it is
The Baxi 102005 is a thermocouple supplied under the Honeywell Q309A2721 reference. It is a flame-sensing device built from two dissimilar metals which generate a small electrical charge when the tip is heated by a pilot or burner flame. That charge energises an electromagnet inside the gas valve, holding the valve open so gas can continue to flow while a flame is proven.
As a Baxi spare, it belongs to the manufacturer's range of gas appliance safety and ignition components and is classified as a thermocouple within the thermocouples spare part group.
Signs this part needs replacing
- The pilot flame lights but goes out as soon as the control knob is released.
- The appliance repeatedly locks out or shuts down shortly after ignition.
- The pilot will not hold at all, even when the knob is held down for an extended period.
- Flame failure faults appear intermittently, with the appliance running normally on some attempts and dropping out on others.
- The thermocouple tip shows heavy sooting, corrosion or a damaged lead, and cleaning the tip does not restore reliable flame proving.
Before you order
- This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.
- Confirm the appliance model and, where available, the GC number against the compatibility list, as thermocouples are not interchangeable between all models.
- Check the part number on the existing component or in the appliance's service documentation matches BAXI102005 before ordering.
- Inspect the pilot assembly and its seals at the same time, as a worn injector or disturbed seal may need attention alongside the thermocouple.
Mechanical
| Part type | Thermocouples |
|---|---|
| Length | 0.1mm |
| Width | 0.1mm |
| Depth | 0.1mm |
Compliance
| Manufacturer part number (MPN) | BAXI102005 |
|---|---|
| GC number | 390-131 |
| Commodity code | 9025 19 80 00 |
| GPC classification | Household Boilers/Furnaces/Tank Water Heaters Replacement Parts/Accessories |
| Alternative numbers | 102005, 102005, 102005, 102005, 1110952 |
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| BAXI BAXI BERMUDA 25/1 | — | — | — | |
| BAXI BAXI BERMUDA 401 | — | — | — | |
| BAXI BAXI BERMUDA 45/3M | — | — | — | |
| BAXI BAXI BERMUDA 552 BBU | — | — | — | |
| BAXI BAXI BERMUDA 57/3 M | — | — | — | |
| BAXI BAXI BERMUDA 675-LFE | — | — | — | |
| BAXI BAXI BERMUDA 675C | — | — | — | |
| BAXI BAXI BERMUDA 675PW | — | — | — | |
| BAXI BAXI BERMUDA 675S | — | — | — | |
| BAXI BAXI BERMUDA 675W | — | — | — |
Showing 10 of 150 compatible appliances.
Fitment listings are a guide, not a guarantee. Plant-room assemblies get modified on site more often than not. Send us the GC number off the data badge and a photo of the existing valve and we will confirm before anything is dispatched.
Documents & drawings
Everything we hold for this part. Where a document exists but we don't hold it, the technical team will source it from the manufacturer — usually the same working day.
manual
BAXI appliance manual — BERMUDA 25/1 (GC 44-077-51)
manualmanualBAXI appliance manual — BERMUDA 401 BBU (GC 44-077-49)
manualmanualBAXI appliance manual — BERMUDA 45/3 MANUAL (GC 44-077-61), BERMUDA 57/3 MANUAL (GC 44-077-63)
manualmanualBAXI appliance manual — BERMUDA 551 CHB(35/55) (GC 44-077-48)
manualmanualBAXI appliance manual — BERMUDA 552 - NG (GC 44-077-50)
manualmanualBAXI appliance manual — BERMUDA 675 BBU / LFE FIRE (GC 44-077-47), BERMUDA 675 C CAT 2TN - FIRE (GC 44-077-45), BERMUDA 675 PW CAT 2TN - FIRE (GC 44-077-43), BERMUDA 675 S CAT 2TN - FIRE (GC 44-077-44), BERMUDA 675 W CAT 2TN - FIRE (GC 44-077-46)
manualmanualBAXI appliance manual — BOSTON 2 40 OF (GC 41-077-80), BOSTON 2 50 OF (GC 41-077-81), BOSTON 2 60 OF (GC 41-077-82), BOSTON 2 70 OF (GC 41-077-83), BOSTON 2 80 OF (GC 41-077-84)
manualmanualBAXI appliance manual — BOSTON 2 40 RS (GC 41-077-85), BOSTON 2 50 RS (GC 41-077-86), BOSTON 2 60 RS (GC 41-077-87), BOSTON 2 70 RS (GC 41-077-88), BOSTON 2 80 RS (GC 41-077-89)
manualmanualBAXI appliance manual — BOSTON 40 OF (GC 41-077-61), BOSTON 50 OF (GC 41-077-62), BOSTON 60 OF (GC 41-077-63), BOSTON 70 0F (GC 41-077-64), BOSTON 80 OF (GC 41-077-65)
manualmanualBAXI appliance manual — BOSTON 40 RS (GC 41-077-66), BOSTON 50 RS (GC 41-077-67), BOSTON 60 RS (GC 41-077-68), BOSTON 70 RS (GC 41-077-69), BOSTON 80 RS (GC 41-077-70)
manualmanualBAXI appliance manual — FS 401 OF - FREE STANDING BOILER (GC 41-077-22), FS 401S OF - FREE STANDING BOILER (GC 41-077-19), FS 501 OF - FREE STANDING BOILER (GC 41-077-23), FS 501S OF - FREE STANDING BOILER (GC 41-077-20), FS 601 OF - FREE STANDING BOILER (GC 41-077-24), FS 601S OF - FREE STANDING BOILER (GC 41-077-21)
manualmanualBAXI appliance manual — FS 401 RS - FREE STANDING BOILER (GC 41-077-13), FS 501 RS - FREE STANDING BOILER (GC 41-077-14), FS 501S RS - FREE STANDING BOILER (GC 41-077-12)
manualmanualBAXI appliance manual — FS 601 RS - FREE STANDING BOILER (GC 41-077-28), FS 601S RS - FREE STANDING BOILER (GC 41-077-25), FS 701 RS - FREE STANDING BOILER (GC 41-077-29), FS 701S RS - FREE STANDING BOILER (GC 41-077-26), FS 801 RS - FREE STANDING BOILER (GC 41-077-30), FS 801S RS - FREE STANDING BOILER (GC 41-077-27)
manualmanualBAXI appliance manual — FS 701 OF - FREE STANDING BOILER (GC 41-077-17), FS 701S OF - FREE STANDING BOILER (GC 41-077-15), FS 801 OF - FREE STANDING BOILER (GC 41-077-18), FS 801S OF - FREE STANDING BOILER (GC 41-077-16)
manualmanualBAXI appliance manual — WM 20/3 RS (GC 41-077-39), WM 30/3 RS (GC 41-077-36), WM 38/3 RS (GC 41-077-35), WM 51/3 RS (GC 41-077-34)
manualmanualBAXI appliance manual — WM 281 RS (GC 41-077-07), WM 381 RS (GC 41-077-05), WM 532 RS (GC 41-077-06)
manualmanualBAXI appliance manual — WM 282 RS (GC 41-077-31), WM 382 RS (GC 41-077-32), WM 512 RS (GC 41-077-33)
manualmanualBAXI appliance manual — WM 40/3 OF (GC 41-077-38), WM 55/3 OF (GC 41-077-37)
manualmanualBAXI appliance manual — WM 402 OF (GC 41-077-09), WM 552 OF (GC 41-077-10)
manualmanualBAXI appliance manual — WM 511 RS (GC 41-077-08)
manualmanualBAXI appliance manual — WM 60/3 RS (GC 41-077-40)
manualNo technical questions yet for this part.
Not sure which part?
Tell the parts assistant what it's going into — the appliance make and model, or the GC number off the data badge — and it will check this part is on the fit list.